Combustion air intake filter

ABSTRACT

An air intake filter for a water heater including a frame structure including a screen, a connector and a receiver positioned to removably engage the connector to position the frame structure at or around an exterior circumferential portion of a water heater.

FIELD OF THE INVENTION

This invention relates to water heaters and burners used in conjunction with such water heaters. In particular, this invention relates to air intake filters for burners used in such water heaters.

BACKGROUND

Water heater burner air intakes/flame traps are sometimes installed in locations that are difficult to clean or that cannot be cleaned without removing the water heater or disassembling the water heater burner apparatus. For example, water heaters for building systems are often installed in “roughed-in” locations such as closets, utility rooms, attics or crawl spaces. These locations are often remote from environmental control systems. As such, they are prone to the build up of particulate matter and debris such as lint, dust, oil and other miscellaneous residue.

Like any combustion device, the efficiency of a water heater burner is at least partially determined by the quality of its air supply. Therefore, the build up of particulate matter around the air intake can lead to performance degradation. Unfortunately, due to cost, packaging and/or other reasons, many water heaters include burner apparatuses that are constructed with no more than adequate air intake filtration for the typical operating environment.

SUMMARY OF THE INVENTION

This invention relates to a filter for the air intake of a water heater burner including a frame structure incorporating an expandable screen, a plurality of connectors and corresponding receivers positioned to engage the connectors to locate the frame structure at a selected position relative the exterior of a water heater. This invention further relates to a filter for the air intake of a water heater burner that can be retrofitted to an operational water heater.

This invention also relates to an air intake filter for a water heater including a frame structure including a screen, a connector and a receiver positioned to removably engage the connector to position the frame structure at or around an exterior circumferential portion of a water heater.

This invention further relates to an air intake filter for a water heater including a first frame structure including a screen, a connector and a receiver, and a second frame structure including a screen, a connector and a receiver, wherein the connector of the first frame structure is positioned to removably engage the receiver of the second frame structure to position the first and second frame structures at or around an exterior circumferential portion of a water heater.

This invention still further relates to a system including a water heater and a filter including a frame structure including a screen, a connector and a receiver positioned to removably engage the connector to position the frame structure at or around an exterior circumferential portion of the water heater.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic partial sectional view of a water heater in accordance with aspects of the invention which emphasizes certain features of the water heater and omits others for ease of understanding.

FIG. 2 is a schematic partial sectional view of another water heater in accordance with aspects of the invention.

FIG. 3 is a schematic partial sectional view of a water heater with an air filter secured to its bottom portion in accordance with aspects of the invention.

FIG. 4 is a schematic partial sectional view of an air filter which illustrates the operation of various aspects of the invention.

FIG. 5A is a schematic front elevational view of an air filter in accordance with aspects of the invention.

FIG. 5B is a schematic top plan view of the air filter in FIG. 5A.

FIG. 5C is a schematic side view of portions of the air filter in FIG. 5A.

FIG. 5D is a schematic top plan view of portions of the air filter in FIG. 5A.

FIG. 5E is a schematic front view of an interior portion of the air filter in FIG. 5A.

FIG. 5F is a schematic front view of an end portion of the air filter in FIG. 5A.

FIG. 5G is a schematic side view of portions of the filter in FIG. 5A.

FIG. 6 is a schematic partial sectional view of a water heater fitted with an air filter in accordance with aspects of the invention which emphasizes certain features of the water heater and omits others for ease of understanding.

DETAILED DESCRIPTION

It will be appreciated that the following description is intended to refer to specific embodiments of the invention selected for illustration in the drawings and is not intended to define or limit the invention, other than in the appended claims.

Turning now to the drawings generally and FIG. 1, in particular, an environment for the implementation of one aspect of the invention is shown. A basic illustration of a water heater 10 includes a water tank/container 12. One skilled in the art will appreciate that the water heater tank 12 comprises several components that serve to receive cold water and store and dispense heated water, as well as other components that, while essential to the operation of the water heater, are not pertinent to the description of this invention. The water heater 10 includes a combustion chamber 14 that, in one preferred embodiment is located below the water tank 12 and is formed by the tank bottom 16, skirt 18 and bottom pan 20. The bottom pan 20 sits on legs 22.

A burner 24 is positioned in the combustion chamber 14. The burner 24 is also positioned to receive fuel from a fuel supply line 28, which connects to a gas valve 30.

The burner 24 is positioned within the combustion chamber 14 and above an opening 34 in the bottom pan 20. The opening 34 is preferably covered with an air inlet/flame arrestor such as an air inlet/flame arrestor 36 of the type as disclosed in any of U.S. Pat. Nos. 5,797,355, 6,142,106 and 6,085,699, for example. Combustion air enters the combustion chamber 14 via the opening 34 and the flame arrestor 36 (when present). The fuel supply line 28 connects to and extends through a door 40 such that the end of the fuel supply line 28 is proximate an end of a venturi 46. Although FIG. 1 shows a venturi 46, one skilled in the art will recognize that other fuel/air supply methods may be utilized such as, for example, tubes, pipes, pathways, conduits and other structures capable of channeling fuel and air to the burner 24. The burner 24 may be connected directly to the door 40 by a pair of connectors and held above the bottom pan 20 by a support. Alternative means of securing burner 24 within combustion chamber 14 may be used.

As shown in FIG. 1, if the venturi 46 is encapsulated within the combustion chamber 14, it will draw all the air it needs to sustain complete combustion entirely through opening 34 located on the bottom pan 20. Typically, this structure offers several advantages such as flame safety protection and some protection from dust or particulate matter. However, for some environments in which water heaters may operate, the dust and/or particulate matter protection provided by this structure may be limited. Particulate matter, including dust, rodents and insects may build up on the lower surface of the air intake screen/arrestor or in the area between the bottom pan 20 and a water heater mounting surface 26 which may lead to performance degradation.

FIG. 2 illustrates a water heater substantially similar to the water heater of FIG. 1 except that it employs a different burner and, accordingly, different apparatus through which to receive fuel and air. Most of the other components of the water heater are the same. Water heater 10 of FIG. 2 also employs a fuel line 28 that extends into combustion chamber 14 and connects to burner 24. An opening 34 receives combustion air for mixture with fuel from fuel line 28.

All of FIGS. 1-3 illustrate an air filter 60 in accordance with aspects of the invention. FIG. 3 illustrates an air filter 60 associated with the water heaters 10 as described in FIGS. 1 and 2 according to various aspects of the invention. In one embodiment as shown in particular in FIG. 3, the air filter 60 includes a frame structure 62 incorporating a screen 64. In a preferred embodiment, the frame structure 62 and the screen 64 are vertically expandable and constructed of plastic. In a particularly preferred embodiment, the screen 64 is integrated into the frame structure 62 as a contiguous plastic component. Alternatively, the frame structure 62 and the screen 64 may be constructed of the different materials including, but not limited to, any of metal, plastic, a composite material or the like.

The air filter 60 may be attached to the water heater 10 to substantially enclose the space bounded by the bottom pan 20 and the water heater mounting surface. In one embodiment, the frame structure 62 and the screen 64 may be expandable to fully enclose the space underneath the bottom pan 20. For example, if the legs 22 are adjustable in height, frame structure 62 and the screen 64 can adjust to match the height of the legs 22 and thus, enclose the area underneath the bottom pan 20. It should be noted that by enclosing the space between the bottom pan 20 and a water heater mounting surface 26, the air filter 60 effectively increases the surface area of the air intake 34. The preferred embodiment has a height dimension of about 2⅝ inches to accommodate standard height legs 22.

The air filter 60 is further adjustable to fit around or at the circumference of the bottom pan 20. As such, the air filter 60 may be fitted to any of the various size water heaters 10 that are currently available or may at some point be available in the future including, for example, water heaters made to metric rather than standard specifications. The preferred embodiment fits to 18 and 24″ diameter water heaters currently available.

FIG. 4 illustrates one aspect of an adjustable connection mechanism of the air filter 60. The adjustable connection mechanism allows the air filter 60 to be secured at or around an exterior circumferential lower portion of water heater 10. The air filter 60 comprises a contiguous frame structure 62 incorporating the screen 64, connectors 66 and receivers 68. The receivers 68 are positioned to receive the connectors 66. In one embodiment, the connectors 66 are located proximal to an end portion of the frame structure 62, and the receivers 68 are located at the end portion of the frame structure distal from the end portion proximal to the connectors 66. In a preferred embodiment, the frame structure 62, being adjustable to fit various size water heaters 10, includes additional receivers 68, distal from the receivers 68 proximal to the one end portion of the frame structure 62, that are also positioned to receive the connectors 66. This provides for the preferred fit to both 18 and 24″ diameter water heaters.

In one embodiment, the connectors 66 are connection posts and the receivers 68 are receiving holes/openings. For example, the connection posts 66 may comprise extensions from the interior of the frame structure 62, each of which include a elongated portion 70 and a head portion 72. The elongated portion 70 of each connection post 66 passes through a corresponding receiving opening 68 while the head portion 72 removably engages the connection post 66 to the receiving opening 68 (and the interior of the frame structure 62). In a preferred embodiment, the frame structure 62 incorporates pairs of corresponding connection posts 66 and receiving openings 68 to achieve each connection, for a combination of frame structural rigidity and ease of attachment/release. However, any number of connectors 66 and receivers 68 may be combined to connect the frame structure 62.

While the frame structure 62 described herein incorporates connectors 66 that may be removably engaged with various receivers 68, one skilled in the art will note that the frame structure 62 may be secured to the exterior of a water heater 10 by a variety of different methods. As such, the invention should not be construed to be limited to the connection methods described herein.

In another aspect, the frame structure 62 further includes a tab 74. The tab 74 is operable to assist in the removal of the connectors 66 from engagement with the receivers 68. For example, in one embodiment incorporating pairs of corresponding connection posts 66 and receiving openings 68 for each frame structure 62 connection, the tab 74 is located at the end portion of the frame structure 62 distal from the connection posts 66. As such, when the corresponding connection posts 66 and receiving openings 68 are engaged, the tab 74 will be adjacent to the removable connection. In operation, the pair of connection posts 66 may be disengaged from the corresponding receiving openings 68 by pushing the head portions 72 of the pair of connection posts 66 toward each other while the tab 74 is depressed.

In a particularly preferred embodiment, the air filter 60 includes a first frame structure and a second frame structure, each with the features described for the frame structure 62 above, wherein the connectors 66 of the first frame structure are positioned to be removably engaged with the receivers 68 of the second frame structure and the connectors 66 of the second frame structure are positioned to be removably engaged with the receivers 68 of the first frame structure. The first and second frame structures may be the same length or different lengths in order to removably attach to circumferential portions of water heaters 10 of various sizes. As such, the circumference of the air filter 10 will be limited only by the number of receivers 68 incorporated on the frame structures.

The embodiments shown in FIGS. 5A-5G illustrate various schematic views of the air filter 60 in accordance with aspects of the invention.

FIG. 6 illustrates an alternative environment for the implementation of the invention wherein the water heater 10 comprises a burner 24 that is open to the combustion chamber 14 and receives combustion air through the flame arrestor 36, which is located at the opening 34. The fuel is supplied to the burner 24 through the fuel supply line 28, which connects to the gas valve 30. The opening 34 is closed tightly by the flame arrestor 36 which admits air for combustion of the fuel gas combusted through the burner 24, regardless of the relative proportions of primary and secondary air used by the burner 24. For example, the opening 34 may be air/gas sealed by a door, except for the intake of the flame arrestor 36. In another embodiment, the combustion chamber 14 is sealed air/gas tight except for means to supply combustion air through the flame arrestor 36 and exhaust combustion products though an exhaust flue. The flame arrestor 36 is preferably made from a thin metallic perforated sheet of stainless steel, such as described in U.S. Pat. No. 6,085,699, for example.

However, similar to as described above, in the operating environment illustrated in FIG. 6, the accumulation of particulate matter on the lower surface of the air inlet screen/arrestor or in the area between the bottom pan 20 and a water heater mounting surface 26 could lead to performance degradation. As such, the air filter 60 is secured around or at the bottom portion of the water heater 10 to enclose the space between the bottom portion of the water heater 10 and the water heater mounting surface 26.

Utilization of the air filter 60 in any of the above-described configurations may reduce the amount of particulate matter entering the air intake of a water heater burner for both new and previously operated water heaters in typical operating environments while increasing the surface area of the air intake in most instances.

Although this invention has been described in connection with specific forms thereof, it will be appreciated that a wide variety of equivalents may be substituted for the specified elements described herein without departing from the spirit and scope of this invention as described in the appended claims. For example, the above description refers to connectors 66 and receivers 68. Alternate structures may be used. Such structures include, but are not limited to, straps, Velcro, snaps, buttons, hooks and the like. Thus, the connectors and receivers referred to in the claims encompass such structures, similar structures and equivalents thereof. 

1. An air intake filter for a water heater comprising: a frame structure including a screen, a connector and a receiver positioned to removably engage the connector to position the frame structure at or around an exterior circumferential portion of a water heater.
 2. The filter of claim 1, wherein the frame structure includes a plurality of receivers and connectors, the plurality of receivers positioned to removably engage the connectors.
 3. The filter of claim 1, wherein the connector comprises a connection post.
 4. The filter of claim 1, wherein the receiver comprises a receiving opening.
 5. The filter of claim 1, further comprising a tab, the tab operable to release the connector from engagement with the receiver.
 6. The filter of claim 5, wherein the connector is positioned proximal to one end portion of the frame structure and the tab is positioned proximal to an end portion of the frame structure distal from the connector.
 7. The filter of claim 1, wherein the frame structure is sited and shaped to enclose a space formed between a bottom portion of the water heater and a surface on which the water heater is located.
 8. The filter of claim 7, wherein the water heater is mounted on legs.
 9. The filter of claim 1, wherein the frame structure is vertically expandable.
 10. The filter of claim 1, wherein the frame structure is a metallic material.
 11. The filter of claim 1, wherein the frame structure is plastic.
 12. An air intake filter for a water heater comprising: a first frame structure including a screen, a connector and a receiver; and a second frame structure including a screen, a connector and a receiver; wherein the connector of the first frame structure is positioned to removably engage the receiver of the second frame structure to position the first and second frame structures at or around an exterior circumferential portion of a water heater.
 13. The filter of claim 12, wherein the connector of the second frame structure is positioned to removably engage the receiver of the first frame structure to secure the first and second frame structures.
 14. The filter of claim 12, wherein the first frame structure includes a tab, the tab operable to release the connector of the second frame structure from the receiver of the first frame structure.
 15. The filter of claim 14, wherein the connector of the first frame structure is positioned proximal to one end portion of the first frame structure and the tab is positioned at the end portion of the first frame structure distal from the connector.
 16. The filter of claim 12, wherein the second frame structure includes a tab, the tab operable to release the connector of the first frame structure from engaging the receiver of the second frame structure.
 17. The filter of claim 16, wherein the connector of the second frame structure is positioned proximal to one end portion of the second frame structure and the tab is positioned at the end portion of the second frame structure distal from the connector.
 18. The filter of claim 12, wherein the first and second frame structures are sited and shaped to enclose a space formed between a bottom portion of the water heater and a surface on which the water heater is mounted.
 19. The filter of claim 18, wherein the water heater is mounted on legs.
 20. The filter of claim 12, wherein the first and second frame structures are vertically expandable.
 21. The filter of claim 12, wherein the first and second frame structures are metallic.
 22. The filter of claim 12, wherein the first and second frame structures are plastic.
 23. A system comprising: a water heater; and a filter comprising a frame structure including a screen, a connector and a receiver positioned to removably engage the connector to position the frame structure at or around an exterior circumferential portion of said water heater.
 24. The system of claim 23, wherein the water heater includes an air intake positioned at a bottom portion of said water heater.
 25. The system of claim 23, wherein the frame structure is sited and shaped to enclose a space formed between a bottom portion of the water heater and a surface on which the water heater is located.
 26. The system of claim 23, wherein the frame structure is vertically expandable. 